To reassure those concerned about wholesale discontinuity between human existence and posthumanity, transhumanists assert shared ground with antiquity on vital challenges and aspirations. Because their claims reflect key misconceptions, there is no shared vision for transhumanists to invoke. Having exposed their misuses of Prometheus, Plato, and Aristotle, I show that not only do transhumanists and antiquity crucially diverge on our relation to ideals, contrast-dependent aspiration, and worthy endeavors but that illumining this divide exposes central weaknesses in transhumanist argumentation. What is (...) more, antiquity’s handling of these topics suggests a way through the impasse in current enhancement debates about human “nature” and helps to resolve a tension within transhumanists’ accounts of what our best moments signify about the ontological requirements for real flourishing. (shrink)